Local water and nutrient availability require plants to adapt their growth and development accordingly. One of the essential plant nutrients is phosphorus (P). Its availability in soils as organic phosphate (Pi) poses a major challenge for crops. Since P is a limited mineral resource, development of crops that perform better with reduced Pi-input is essential. Previous Pi-starvation studies reveal that plants deploy local and systemic signaling to increase Piuptake and adjust plant growth. A long-term response to low Pi involves modifying gene expression, however, how plants sense low Pi and consequently generate early priming signals to activate this gene expression is much less understood. Understanding the early processes and signals are vital to improving the efficiency of Piuptake, distribution, and ultimately plant architecture. The PiLESS project aims to characterize early Pi-depletion signaling by real-time observations of physiological and molecular responses and biochemical identification of early Pi-signaling components. These
novel components will be validated using a multiplexed CRISPR/Cas9 gene-editing approach. Moreover, we will develop a Pi-sensor, applicable in Arabidopsis thaliana, tomato and other crops, to monitor Pi-depletion responses in plants. These insights into the early signaling processes will reveal how plants overcome low Pi-conditions